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I am in the process of building this amplifier. I have a very solid understanding of solid state electronics however this is my first tube amplifier.My question is with regards to the 6CY7 schematic, it states one 6CY7 per channel, left and right. I have enclosed how I envision the wiring of the 2(qty) tubes to get the left and right channel, am I seeing this correctly? (see enclosed)Also I will be using Hammonds 125DSE instead of the Edcor XSE but I am not sure what secondary windings to use as there as there is no mention of the o/p of the secondary on the Edcor spec.

Any assistance would be truly appreciated!

Regards,

Glen

Attachment:

tube schematic questions.jpg

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I have enclosed how I envision the wiring of the 2(qty) tubes to get the left and right channel, am I seeing this correctly?

No. I think the point you're missing is that, unlike the small voltage amplifier tubes (12A*7, etc.), the two sections of the 6CY7 have radically different characteristics. The driver circuit MUST use section 1 and the power section MUST use section 2. I chose to wire one tube for each channel.

Here is a picture showing the tube socket and how I wired my amplifier.

Attachment:

Stage wiring.jpg

The labels in white are the 6CY7 pin connections and the labels in blue are the connecting components.

As for the Hammond 125DSE, any transformer primary impedance depends on the load impedance; hence the name "transformer". So for a 5kΩ primary load you'd use the "white" lead for 16Ω speakers, the "yellow" lead for 8Ω speakers, and the "green" lead for 4Ω speakers. The transformer reflects the speaker load back to the primary depending on the turns ratio of the transformer. All these connections will result in a 5kΩ primary load impedance.

Does this help.

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